Patent DE-102007039075-A1 (DE)
Title: Continuous casting plant for processing liquid steel to strand-like endless materials e.g. slabs, comprises mold, distributor for filling the mold with liquid raw material, and strand outlet to discharge solidifying strands from the mold
Inventor: STARK JOHANNES
IPC: B22D11/106
Filed: 2007-08-18
Abstract: The continuous casting plant for processing liquid steel to strand-like endless materials such as slabs, billets, beam-blanks, pre-blocks and thin slabs, comprises a mold (1), a distributor (3) for filling the mold with a liquid raw material, and a strand outlet (4) for discharging the solidifying strands from the mold. The distributor is connected with the mold over an immersion nozzle (2), which introduces the liquid raw material into an inner chamber of the mold without ambient air and is implemented in double-walled sections with an inner wall and an outer wall. The continuous casting plant for processing liquid steel to strand-like endless materials such as slabs, billets, beam-blanks, pre-blocks and thin slabs, comprises a mold (1), a distributor (3) for filling the mold with a liquid raw material, and a strand outlet (4) for discharging the solidifying strands from the mold. The distributor is connected with the mold over an immersion nozzle (2), which introduces the liquid raw material into an inner chamber of the mold without ambient air and is implemented in double-walled sections with an inner wall and an outer wall. The inner wall and the outer wall limit a protection chamber (5) surrounding the immersion nozzle in section-wise manner. A precursor for preventing diffusion of oxygen or oxygen-containing gas particles is provided in the raw material through the inner wall. The precursor in the immersion nozzle is formed by filling the protection chamber with an inert gas such as argon. An external tube forming the outer wall is pushed over the inner wall for the formation of the double-walled areas of the immersion nozzle. An upper gasket and a lower gasket for closing the protection chamber are intended at the front sides between the inner and the outer walls. The external tube covers more than 90% of the immersion nozzle and ends above the bath level of the liquid raw material in the mold without immersing into the raw material. The outer wall is made of ceramic material, which is a porous oxide-ceramic fiber composite material. The matrix material is aluminum silicate with a portion of 65-97 wt.% of aluminum oxide and the fiber material is aluminum oxide fiber or aluminum silicate fiber soaked with matrix slurry. The matrix material and the fiber material cause homogeneous porosity of the ceramic materials during the production process when sintering. The wall strength of the outer wall is 2 mm. The outer wall is surrounded by an additional thermal insulator. The protection chamber has a gas inlet and a gas outlet. The gas inlet for continuously introducing the inert gas into the protection chamber is connected with a gas supply. A positive pressure of 0.1 bar is present in the protection chamber relative to the ambient pressure. The gas inlet and the gas outlet are formed by a gap between the inner and the outer walls. An independent claim is included for an immersion nozzle useful in a continuous casting plant.